1. Field of the Invention (Technical Field)
The present invention relates to apparatus and methods for machining soft materials, particularly cuts of meat, and especially to an apparatus for cutting fatty tissue from meat.
2. Background Art
Under many circumstances, it is difficult to cut soft materials because the soft material may tend to deform, rather than cut, under the pressure of the cutting blade. In commercial meat processing facilities, such as beef processing plants, slabs of meat must be cut efficiently and quickly. Particularly, it is necessary to shear cut fatty tissue from lean tissue to obtain a cut of meat with a specified desirable amount of fat intact upon an underlying layer of lean meat. Currently in most commercial meat processing plants, fatty tissue is cut from carcasses in generally the same manner as has been employed for a century: individual laborers wielding large (sometimes two-handled) trimming knives, which knives are manually drawn across the cut of meat to sever a portion of fat. Typically, the worker must stand immediately proximate to the carcass and pull the knife toward the worker to trim a certain amount of fat while leaving a specified amount of fat upon the lean tissue. Provided a sharp edge is maintained upon the knife, the fat is severed with a sweeping shear cut.
Again, however, it is difficult to accomplish a smooth shear cut of a soft material such as fat, especially if the cutting blade is not optimally sharp. Further, the trimming of meat by manual laborer is inefficient and poses physical dangers to the worker. Ideally, all meat cutting in commercial, high-volume facilities is performed by machines, both to boost efficiency and reduce costs, as well as to remove workers from the dangerous processing line.
However, a shear cut, to be effectively accomplished, preferably involves the application of a blade having an oblique angle of attack, i.e., the line defining the cutting edge is neither parallel nor perpendicular to the direction of blade movement. Shear cuts are best accomplished when the blade is tilted with respect to the material being cut; ordinary examples of this principle are the angled disposition of scissors blades, or the way a skilled chef uses a shallow back and forth action when slicing very soft material such as tomatoes or fresh bread.
A need remains for a method and apparatus for automated shear cutting of soft deformable materials, particularly fatty tissue on meat. Against this background, the present invention was developed.